Wikipedia defines impact investing as “investments made into companies, organizations, and funds with the intention to generate a measurable, beneficial social or environmental impact alongside a financial return." It is a form of socially responsible investing that serves as a guide for various investment strategies.
Increasingly, investors recognize that environmental, social and governance (ESG) considerations can have an impact on the financial performance of investments and long-term shareholder value. Responsible investment is a viable approach to achieve competitive investment returns, while ensuring that their money is managed in accordance with ESG issues.
There are a number of structures available today such as social impact bonds, SRI mutual funds, venture capital funds for clean tech, capital aggregation models etc.
Here are some sources of information about impact investing: